1. Grindelia ciliata (Nutt.) Spreng. (goldenweed)
Prionopsis
ciliatus (Nutt.) Nutt.
Haplopappus
ciliatus (Nutt.) DC.
G. papposa G.L. Nesom
Pl. 237 a, b;
Map 982
Plants annual or
less commonly biennial. Stems (10–)40–120 cm long. Stem leaves sessile, the
blades 2–8 cm long, oblong to ovate or oblong-obovate, cordate at the base and
strongly clasping the stem, rounded or bluntly pointed at the tip, the margins
with many narrow, coarse, sharp teeth, these mostly with a spinelike or
bristlelike extension at the tip, the surfaces appearing not or only slightly
resinous, with usually moderate glandular dots, but these inconspicuous and only
slightly differing in color from the surrounding leaf tissue. Inflorescences of
solitary heads or loose clusters at the branch tips. Receptacle 1.5–3.0 cm in
diameter. Involucre 10–15 mm long, the bracts in 3–5 unequal series, at least
those of the outer few series with the tip spreading to recurved or curled
outward. Ray florets 25–50, the corolla 10–20 mm long. Disc florets perfect or
some of the inner ones functionally staminate, the corollas 6–8 mm long. Pappus
of numerous (30–60) bristles, 3–10 mm long, these minutely barbed, fused at the
base, persistent at fruiting or sometimes shed tardily as a unit, those of the
outer series shorter, stouter, and slightly thickened toward the base
(awnlike), straw-colored to light orangish tan. Fruits 2–4 mm long, light gray
to whitish gray. 2n=12. August–September.
Possibly
introduced, uncommon in southwestern and west-central Missouri, introduced
sporadically elsewhere in the northern half of the state and in a few southern
counties (Nebraska south to New Mexico and Texas; introduced west to
California, east to Iowa, Illinois, Michigan, and Maryland, and south to
Louisiana). Glades and upland prairies; also railroads, roadsides, and open,
disturbed areas.
Goldenweed
presumably is native to portions of the Great Plains, but it has dispersed
along railroads and highways to extend its range in all directions. In
Missouri, its status is unclear. Arguments in favor of it being a rare native
at some sites are the fact that it has been collected in some reasonably
undisturbed prairies and glades in the western half of the state, and also that
it was collected as early as 1882 in southwestern Missouri (introduced
occurrences in most other states were all far more recently documented). On the
other hand, the large majority of specimens, even those collected as early as
the first decade of the 1900s, clearly document nonnative occurrences in
disturbed habitats.
Steyermark
(1963) and most earlier authors treated this species as a member of the large
and polymorphic genus Haplopappus Cass. A series of morphological,
anatomical, and molecular studies by various investigators (summarized by Lane
and Hartman, 1996) resulted in the gradual dismemberment of that genus in North
America into a large number of smaller, more homogeneous groups with diverse
affinities in the tribe Astereae. A number of these studies agreed that the
species known as H. ciliatus was closely related to species of Grindelia.
Following Correll and Johnston (1970), the generic name Prionopsis Nutt.
was resurrected to accommodate this one unusual species. Nesom et al. 1993)
reviewed the data that had accumulated on these genera and concluded that P.
ciliata was best classified as a morphologically atypical member of Grindelia,
a conclusion that has been followed by recent authors (Kartesz and Meacham,
1999) and also in the present work. However, their renaming of the species as G.
papposa was superfluous.